Reloder 25 in a 6.5 stw

I have some rl25 and I'm not quite sure where to start. I have read that it can be a difficult powder to work with at times and it has me apprehensive. I took a guess at 73.5gr start and 75gr max. Looking at load data for 7mm stw bullets with similar S.D.'s can take charges up to 81gr and has me doubting now. I been really busy at work and don't get alot of range time so I want to start close if I can. The bullet is 120gr ttsx. Thanks, tim